Dekoni Audio X HIFIMAN Cobalt

General Information

Dual 3.5mm

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Dekoni x Hifiman Cobalt: A New Kind of Blue
Pros: Airy, open-ish, well-balanced sound with nice soundstaging and good clarity & separation.
Lightweight for comfortable, easy all-day listening.
Low impedance combined with the light weight makes them a reasonable mobile option.
Cons: Sound can get a bit bright/crowded in the upper-mids and higher frequencies on some tracks with the Fenestrated Sheepskin ear pads without EQ, or if pushed too hard with an amplifier. This is not as noticeable with the Velour ear pads, but you lose some of the low-end oomph when swapping from the Sheepskin pads to the Velour pads.

Dekoni x Hifiman Cobalt: A New Kind of Blue​

Review of the Dekoni x Hifiman Cobalt headphone by @dilbertprogrammer
Written June 22, 2023

Table of Contents​

  1. Preface
  2. Introduction
  3. Price and Specifications
  4. What’s In The Box?
  5. Build, Design, Comfort
  6. Music Source and Chain Components used for Listening Evaluation
  7. Personal Preferences
  8. Examples of Listening Evaluation Tracks
  9. Sound
  10. Comparisons
  11. Wrap-Up, Summary and Conclusion

1. Preface​

This review was written after spending approximately one week with a new Dekoni x Hifiman Cobalt headphone on loan from Dekoni as part of their USA Loaner Tour in June 2023.​

2. Introduction​

The new Dekoni x Hifiman Cobalt is a closed-back, dynamic driver headphone made by Dekoni in partnership with Hifiman. This is the sophomore collaboration between Dekoni and a headphone manufacturer. The first was the Dekoni Blue (a planar magnetic headphone) that Dekoni developed with Fostex.​
The Dekoni x Hifiman Cobalt sports new Hifiman dynamic drivers which utilize a carbon-coated diaphragm. By experimenting with material placement behind the drivers in the ear cups, and designing new ear pads, Dekoni tuned the headphones to deliver a well-rounded sound signature.​

3. Price and Specifications​

The Cobalt retails for $499.99 and has the following specifications:​
  • 16Ω impedance, 101dB sensitivity
  • 45mm dynamic transducer
  • 20-20kHz frequency range
  • 318g weight (with Fenestrated Sheepskin ear pads)
  • Dual 3.5mm

4. What's In The Box?​

You get:​
  • Cobalt headphones with Elite Sheepskin ear pads installed
  • Single-ended cable (dual 3.5mm to 3.5mm with 6.35mm adapter)
  • Elite Velour ear pads

5. Build, Design, Comfort​

In the hands, you immediately notice how light the Cobalt is. It's light weight (318g, published) makes wearing them "all-day comfortable."​
With the Fenestrated Sheepskin ear pads installed, the Cobalt weighed in at 308g on my scale.​
The Cobalt's monoblock foam headband is familiar from having owned several Hifiman headphones with it. I have a larger head and sometimes start to get a hot-spot around the center of the headband, but a quick adjustment resets comfort fairly easily.​
The fenestrated sheepskin ear pads are plush, roomy and very comfortable.​
The velour ear pads are also comfy, and do a good job of taming the upper-mid and high frequencies.​
The length of the supplied cable is fine for desktop use and the material is plenty flexible. The "L"eft and "R"ight markings on the connectors are tough to see without good lighting.​
I like the muted/matte finish of the black/blue Cobalt. It is obvious from the markings that the headphone is a Dekoni & Hifiman collaboration, as the earcups have the Dekoni branding and the headband has the Hifiman branding.​
Swapping the ear pads was fairly straightforward following the guidance provided in the video online.​
With the ear pads removed, you can see the amount of space that surrounds the driver grilles where the foam baffle inserts (currently in production at Dekoni) can be placed to tweak sound.​

Daily Driver Usability and Comfort​

I was easily able to wear the Cobalt all day.​
I was also able to use the Cobalt on video calls and not be bothered by the sense of isolation typically experienced with closed-back headphones.​

6. Music Source and Chain Components used for Listening Evaluation​

  • Sources:
    • Analog - Technics SL-Q202 (Ortofon 2M Black) >> ifi Zen Phono
    • Digital - Denafrips Ares II
  • Headamps:
    • Burson Soloist 3XP (V6 Classic Dual Opamps x 4)
    • Violectric V280B
    • Schiit Lyr+ (GE 5692)
    • xDuoo TA-20 (Mullard 12AU7)

7. Personal Preferences​

I am not an audio professional. I am just a simple audio fanatic (who is also an IT professional) strapped to a desk for long hours everyday that will enjoy audio when not on video calls for work.​
Before I get into the Sound section, I want to share my personal listening preferences to give some perspective. Though I have both hardware and software EQ options at my disposal, I typically prefer not to utilize them for the most part. I'm blessed to not be overly sensitive to any specific frequencies, nor do I have any that always need to be boosted.​
I instead want each headphone to be able to present itself as intended (at least initially), and then if deemed necessary, make mild tweaks by either utilizing a different amplifier in my chain or changing earpads (if an available option). Making EQ adjustments is always a last resort for me. I ultimately found I preferred the Cobalt with some EQ tweaks when using the Fenestrated Sheepskin ear pads which I will cover below.​
For my listening sessions I prefer emotional over analytical, warmth and color over sharp and linear. How does the music make me feel? Do I experience any unsolicited emotional (e.g., joy, sadness) or physical responses (chair dancing)? Have the components been able to disappear while listening?​
I listen to a wide variety of music genres, but mostly subgenres of rock and alt music. During the week I had the Cobalt I listened to many, many tracks. :)

8. Examples of Listening Evaluation Tracks​

Here are just some of the tracks I enjoyed while listening –​
  • "The Teacher" by Foo Fighters
  • "Empires" by The Smashing Pumpkins
  • "You Must Burn!" by Metallica
  • "Break Free" by Dave Matthews Band
  • "Emotional Sickness" by Queens of the Stone Age
  • "Nobody Wants to Die" by Rival Sons
  • "Sacred The Thread" by Greta Van Fleet
  • "Be Yourself" by Wilder Woods
  • "Eye Patch" by De La Soul
  • "Bounce Back" by White Denim
  • "Paddle to the Stars" by The Dip
  • "Dreamer Of The Dawn" by Crown Lands
  • "Ocelot" by Phish
  • "Seasons" by Chris Cornell
  • "Sugar Babies" by Spoon
  • "Heart Medicine" by Judah & the Lion
  • "Gila Monster" by King Gizzard & The Lizard Wizard

9. Sound​

All of the subjective notes below are my thoughts and opinions observed while listening to the Cobalt.​

First Sound Impressions:​

Mostly neutral, slightly bright, open-ish welcoming sound.​
Given the ultra low impedance I found when using (the more powerful) XLR balanced output on my headamps it was best to use either low gain or use the single-ended output as the upper frequencies became too pronounced and a bit crowded (without EQ).​

Listening Evaluation Sessions' Notes:​

Bass: Not strong, but plenty decent and sufficient.​
Mids: Forward, especially with vocals, acoustic/string instruments and wind instruments. Tonality and timbre are good.​
Highs: Clear, albeit bright. Lowering the 8.8k and 9k frequencies a few dB via EQ took the edge off and made for a less fatiguing listening experience (when using the Sheepskin ear pads).​
Resolution: While not super-fine, clarity is satisfactory and details are crisp.​
Soundstage: Surprising amount of width to the soundstage for a closed-back headphone.​
Imaging & Layering: Placement of instruments and voices is up to scratch, but can get crowded in the upper-mids and highs when tracks get busy.​
Separation: Voices and instruments have great separation, but the overall presentation can feel congested for some recordings.​
Dynamics: Punchy. Drums and bass guitar really hit with impact.​


This is where I ultimately landed with EQ (of course YMMV based on your ears) tweaks using PEACE on Windows :wink:

10. Comparisons​

I compared the Cobalt to two headphones in my collection.​
Focal Elegia (with Dekoni Elite Hybrid ear pads installed), the only closed-back dynamic headphone in my collection (which currently has a $399 MSRP) and the Hifiman Edition XS which is similarly priced (it currently has a $449 MSRP), also made by Hifiman, has the same headband, but is an open-back planar magnetic headphone.​

In comparing the Cobalt to the Elegia, the Elegia:​
  • is noticeably heavier
  • has greater clamping force
  • does not feel as open (much more isolated)
  • has stronger bass
  • has a more narrow soundstage
  • has greater resolution
  • has less separation
  • has stronger dynamics
In comparing the Cobalt to the Edition XS, the Edition XS:​
  • has similar clamping force
  • has a more V-shaped, less-balanced frequency response (mids? What are mids??)
  • is less airy
  • has stronger bass
  • has a wider soundstage
  • has greater resolution
  • has on-par separation
  • has on-par dynamics

11. Wrap-Up, Summary and Conclusion​

My listening enjoyment grew each day as my brain calibrated to the new headphones and the headphones continued to burn in.​

I found the openness of the closed-back Cobalt to be very pleasing, and that I preferred the Velour ear pads over the Sheepskin ear pads.​

I'm excited to try the Cobalt with other flavors of Dekoni ear pads when they become available (fingers crossed for Choice Suede!), and the foam baffles that are in production.​
Thank you to Dylan and Dekoni for allowing me to participate in the Cobalt loaner tour!​
If you are in the hunt for a lightweight open-sounding closed-back dynamic driver headphone, the Cobalt is a solid choice!​
You can purchase the Cobalt from Dekoni here: Dekoni x Hifiman Cobalt Closed-Back Dynamic Headphone
Last edited:
Sonic Defender
Sonic Defender
Please define what you mean by resolution and dynamics.
@Sonic Defender

Resolution - level of fineness/detail/texture in the music; ability to present the more subtle details in the music.

Dynamics - ability to convey energy/intensity/power in the music, via a notable variation/delta in the delivery of the sound (e.g., punch, slam, etc.)
I bought the Elegias and I couldn’t be happier. Added a hart audio 4.4 balanced cable and Dekoni custom foams from amz Japan. Really, really appreciated your analysis of the two to the point where I am going to end up owning both very soon. Thank you again!


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